This invention relates to vehicle head restraints.
Head restraints are an important safety feature of a vehicle seat. Although some head restraints are integral with the seat, most head restraints are attached to the top of the seat. If the head restraint is not integral with the seat, rods extend from the seat into the head restraint. These rods help maintain the position of the head restraint relative to the seat.
Articulating, or folding, head restraints are desirable. An articulating head restraint rotates from an upright position to a stowed position. An example of an articulating head restraint is shown in U.S. Pat. No. 5,738,411, issued to Sutton et al. In articulating head restraints, the relative position of the head restraint to the seat changes as the seat moves from the upright (design) position to the stowed position. The head restraint rotates forward or rearward so as to avoid contact with a preceding seat.
One problem with an articulating head restraint is the need to maintain its stability in the upright (design) position. Since the articulating head restraint has at least one joint, the head restraint will tend to move about the joint even in the design position.
Due to the greater number of moveable parts in an articulating head restraint, there is a greater likelihood that the head restraint will develop free play. “Free play” is an undesired and usually slight displacement of the head restraint from its design position. Free play is sometimes associated by consumers with a lack of sturdiness or quality. Minimization of free play is thus important.
Two sources of free play in an articulating head restraint are the locking mechanism and the rotational armature. The locking mechanism holds the head restraint in the upright position. If there is free play, the head restraint may tilt from the design position when the seat is unoccupied, an occupant of the seat could also feel some motion of the head restraint, or undesirable squeaks, or rattles could occur. In either circumstance, the head restraint could be considered to be poorly made and constructed.
An additional source of free play is due to the construction of the armature and bracket. One end of the armature is first placed through a first bracket hole. The other end was then placed through a second bracket hole. In order to facilitate the insertion of the second end of the armature into the bracket, the second bracket hole has a slightly larger diameter than the first bracket hole. Although a bushing is used, the armature thus tends to move laterally on its axis within the second bracket hole, again increasing the free play of the head restraint mechanism. Again, a consumer could infer that the head restraint was not well made.
Thus, articulating head restraints with minimal free play are very desirable.